Sadly, there is no penalty for breaking your oath. I like to believe that if the designers had enough time to release the game properly, that would have been in there.
Along with variations like how to cure Scabban (if you so chose). That could have been interesting...
And I do suspect that you'll be going back to the crypt again soon... if you haven't completed the warrior guild quests. Many quest items don't appear until you have the quest.
And feel free to start new threads on game updates. Helps people to see them better, it does...